A 16-year-old girl suffered back and leg injuries when she was hit by a car while riding her scooter in Pinjarra this morning.
The collision happened about 5.45am near the corner of Pinjarra Road and Beacham Road.
The RAC rescue helicopter was deployed but stood down a short time later.
St John Ambulance paramedics drove the teenager to Peel Health Campus with possible serious injuries.
Earlier this morning, a man had to be freed from his car after crashing into a tree in Mundijong.
It is understood his car left the road near the corner of Mundijong Road and Adonis Street just after midnight.
The passenger knocked on a nearby resident's front door and asked them to call an ambulance.
The driver was trapped and drifting in and out of consciousness.
Paramedics rushed him to Royal Perth Hospital under priority.
Anyone with information is asked to call Crime Stoppers on 1800 333 000.